A system has been used which tracks a photographed target using template matching for applications, e.g., confirmation of safety within a building and monitoring for finding of defectiveness of a product. In such a system, when a camera that shoots an image moves or when a photographed target moves, how the image of the target looks changes. Accordingly, a transforming target would be traced, and hence a template to be used needs to be automatically updated.
As an example, there is an example in which, when a desired pattern is indicated in one frame of an input moving image, a pattern that is the most similar to the indicated pattern is detected in another frame. A method is known in which a detected pattern is replaced with an indicated pattern to update a template, and patterns are detected repeatedly to trace a desired target.
Patent document 1: Japanese Laid-open Patent Publication No. 1-315884